Testing machine



May 28, 1929. w. w. MCLAURIN TESTING MACHINE Filed Oct. 19, 1925Patented May 28, 1929.

warren srarss tut ears? ries- WILLIAM. W.'1VI LAURIN, OF BROOKFI ELID,MASSACHUSETT$.

TESTING MACHINE- Application filed fictober 19, 1925. Serial No. 63,267,

This invention relates to testing machines, and more especially tomachines for testing the strength or adhesiveness of the gumming onsealing tape, and the like.

Sealing tape usually consist-sot a strip of paper or cheap fabric coatedon. one side with an adhesive and is much used for staying the cornersor edges of cardboard or fibreboard boxes, for sealing together theflaps of cartons, and numerous other uses. it is important that the tapeshall not only securely hold the parts united thereby after the adhesivehas dried, but that it shall also hold these parts in their sealedpositions immediately after the tape has been applied to them and when,consequently, the adhesive union is weakest. For example, the tape usedto seal cartons should have suiiicient strength "to hold the cartonflaps closed in'iniediately after the tape has been applied to them, andthus avoid the necessity of using any other means for holding the flapsin their sealed positions.

l urthermore, sealing tapes andstays are also manufactured in differentgrades and require adhesives of different strengths, and it is importantthat these diii'ercnt qualities or grades be kept up to standard. To dothis requires some means for determining the strength of the adhesiveunion made by a given grade or quality of sealing tape. The

present invention deals with the problem presented by these conditionsand it alins to devise a simple and thoroughl practical 11121- Themachine shown comprises two brack-.

ets 2 and 3 supported on pivots i and 5, re spectively, which aremounted in the upper ends of standards 6 and 7 These standards areconnected by and supported on a base 8. At one side of the pivot 4; thebracket 2 is provided with a long fiat jaw 10, while an the testing arm12 projectsiroin said bracket at'the 0pposite side or said plvot andsupports a weight 1a, this arm being graduated, as indi cated atjl6,Fig. 1.. Pivoted on the bracket 2 is another jaw 18'liaving a rearwardlypro j ecting arm through which is threaded an ad j Listing screw 20, thelower end of this screw bearing on the arm 12 and serving, whentightened up, to :torce ,the awv 18 firmly against the jaw 10. "Similarparts are associated with'the bracket 3, said parts including a aw llanda weight arm 13 to receivea weight 15. An upper jaw 19 cooperates withthe jaw .11 and is arranged to be clamped thereagainst by an adjustingscrew 21.

has

The two pairs of jaws may be madeto grip I and securelyhold' two testingplates 22-and 23, respectively, which'may be made of metal,

butmore usually consist of fibreboard card board, or other material ofthe same nature as that to which the sealing tape s to be applied. Arest 2tis formed integral with a bar 25 which connects the two standards6.

and 7, and is arranged to support the marginal portions of the plates 22and 23 opposite to the margins thereof WlllCll are gripped by therespective jaws.

Assuming, for example, that itis desired to test the strength, whilenioist, ot the adhesive coating on sealing tape intended especially tobe used in sealing carton, flaps, two sections of cardboard'of whichcarton flaps are made, would be inserted in the jaws and w. uld iorn'ithe plates 22 and 23, these parts being clamped securely in their properpositions. A sealing strip S then WOtllClbB m.ois-' tened and applied tothe margins of the plates, as shown in Figs. 1 and 2,. thus adhe-ysively securing them together. The weights i l and 15 next would bemoved gradually outward on their respective arms 12 and 13 thus tendingto disrupt the adhesive union between the plates and the strip. Theforce i so applied could be gradually increased (by adjusting theweights until a relative slip starts between ,thesealing tape and one of3 l2 and 13 may he graduated either in pounds, or thegraduations'inaysimply be numbered, so that in either event a relativeindication oi the strength of the adhesive union will be given.

it will he observed that the mounting of the brackets 2 and 3 permits arelative move" rnent of the plates 22 and 23 resembling the plates 22 or23. l The wei ht arms L a inoveme'nt of the carton flaps as they tend top open under their own resiliency after being. sealed, so that theconditions under which carton sealing tape is used are closely simu-'lated. The machine is equally useful, however, in testing gummed oradhesively coated tape used for other purposes. In some cases,

it may be advantageous to make the plates 22 and 23 or" metal and tocover them, at least on'one side, with paper, cardboard, or othervmaterial to'which the sealing tape is to be applied. This isparticularly desirable where the sealing tape to be tested is intendeiior general use in sealing packages and the like,

and where, consequently, it is desired to testits adhesiveness towrapping paper.

Aft-er standards for dill erent grades have been worked out and theadjustment of the weights i l and consequently have been determined forcorresponding grades, it is simk ply necessary to set these weights tothe desired points and then apply the sealing tape and see whether ornot it will hold the test plates 22 or 23 against the disruptive forcesWhile I have herein shown and described the best embodiment of myinvention that I have sofar devised, it will be evident that theinvent-ioninay be embodied in many other forms without departing fromthe spirit or scope thereof. v 1

Having thus described my invention, what I desire to claim as new is 2.V

l. Ina testing machine, the combination of two members arranged to bejoined by a stripoiisealing tape'adhesively united to at least one ofsaid members, means supporting said members for relative swingingmovement in a'direction'tending to disrupt said adhesive union, meansadjustable to gradual ly increase the disruptive strain, and a scaleassociatedwith said means for indicating the rclative intensity of thestrain so applied.

' 2. In a testing machine, the combination of two plates arranged edgeto edge, whereby the may be 'oined b a strin of adhesive tape, means forsupporting said plates for relative swinging movement to separate themand thereby, to disrupt the adhesive union between one of said platesand said tape, and

means for indicatingthe relative intensity of the strain so applied.

3. In a testing machine, the combination gummed papers, or the adof twoplates, means for supporting said plates for swinging movement aboutaxes lying parallel to the plates, said axes being so spacedthat theplates may be swung into an edge to edge relationship, whereby theplates Imay be joined by astrip of adhesivetape, a rest for supportingsaid plates in said relationship, a weight arm attached to one of saidplates, and a weight adjustable on said arm to swing said plate andthereby to move the plate in a direction tending to disrupt the unionbetween one of said plates and the tape,

and 'rad'uations on said arm for indicating Y the relative intensity ofthe force so applied. 4 In a testing machine, the ccu'ibination ot abracket, meanssupporting said bracket for swinging movement, a graduatedweight arm projecting from said bracket, weight adjustable on said arm,a testing'plate carriod .by'said'bracket, and a part cooperating withsaid plate and arranged to be adhesive'ly united thereto by'a sealingstrip.

In a testing machine, the combination of two bracketsmounted to swing onsubstantially parallel axes, weight arms project- 7 111g i'roni saidbrackets, weights adjustable on said arms, said brackets being arrangedto support two testing plates, one on each bracket, so that the edges ofsaid plates will substantially meet in a single plane and can be swungaway from each otherby moving said weights outwardly along therespective arms of said brackets, and-a rest for supportmg said platesin said plane. V

In a testing machine, the combination with tWO JELWS each adapted togrip a test alate. said aws b6111 snaced a Jart whereb the two platesmay be positioned in substantially an edge to edge relationship wherethey may be. oined by a strip of adhesive'tape, means tor supportin saidjaws tor swinging movement about substantially parallel axes to applystrain to the adhesive union between said plates and tape, and means forindicat ing the relative intensity of the strain so applied.

7. In a testing machine, the combi ation with two jaws each adapted togrip a test plate, said aws being spaced apart, whereby the two platesmay be positioned in substantially an edge to edge relationship wherethey may be joined by a strip ofadhesive tape,

means for supporting said plates for swinging movement aboutsubstantially horizontal parallel axes to apply strain to the adhesiveunion between said plates andtape, means for relatively swingin saidjaws aboutsaid axes, and means for indicating the relative intensity or"the strain applied by said swinging movement.

WILLIAM w. MGLAURIN.

